• Title/Summary/Keyword: Infiltration analysis

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A Study on the Characteristics of Infiltration of Sea Dyke by Field Investigation and Seepage Model Test (현장조사와 침투모형시험을 통한 방조제 침투특성 연구)

  • Park, Choon-Sik;Kim, Jong-Hwan;Lee, Sun-Il
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.4
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    • pp.247-256
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    • 2012
  • The purpose of this study is to decide the permeability and the rate of flow in a way of both site investigation and backward analysis and the most reasonable numerical analysis by performing a seepage model test for measuring the deformation swept volume of the embankment body in order to review a stability of the sea dyke being composed of multi-layers depending on variation of infiltration. As a result of the review, it could be forecasted that sweeping loss would be taken place at the boundary between bed protection works and embankment materials of the sea dyke due to a permeability difference of the multi-layered bed foundation structures and the sea dyke deformation would be occurred as a result thereby. As result of a numerical analysis for the seepage model test, it could be observed that critical velocity method was found to be smaller than the numerical analysis value but its tendency was similar and therefore it was judged that this method could be applied for the actual cross section.

A STUDY ON EROSION (CAUSES AND REMEDIES) BASED ON HYDROLOGICAL DATA

  • K.M. Ibe, Sr;H. Krynen
    • Water Engineering Research
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    • v.2 no.4
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    • pp.269-276
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    • 2001
  • The project concentrates on an hydrological analysis. The analysis consists of rainfall, infiltration, Determination of runoff and sediment yield. The risque of erosion and the control measures are related to the slopes and land use. Therefore the first approach to erosion must be correct land use based on land classification. Basically there are two types of mechanical protection works; Drainage and Storage. Realization of a drainage system will be very costly and therefore temporary storage is preferred. For farmland in flat areas hardly any measures are needed. For farmland on slopes temporary storage can be effected by applying tillage with ridges within contour bunds. Along roads infiltration pits should be constructed and in areas with houses, the solution to avoid runoff will be water harvesting.

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Fabrication Process and Analysis of Thermal Properties of High Volume Fraction SiCpi/Al Metal Matrix Composites for Heatsink Materials (반도체 heatsink용 고부피분율 SiCp/Al 금속복합재료의 제조공정 및 열적특성분석)

  • 이효수;홍순형
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.11a
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    • pp.58-62
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    • 2000
  • The fabrication process and analysis of thermal properties of 50~76vo1% SiCp/Al metal matrix composites(MMCs) for heatsink materials in electronic packaging were investigated. The 50~76vo1% SiCp/Al MMCs fabricated by pressure infiltration casting process showed that thermal conductivities were 85~170W/mK and coefficient of thermal expansion(CTE) were ranged 10~6ppm1k. Specially, the thermal conductivity and CTE of 71vo1%SiCp/Al MMCs were ranged 115~156W/mK and 6~7ppm/K. respectively, which showed a improved thermal properties than the conventional electronic packaging materials such as ceramics and metals.

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The Study of Fat Infiltration Ratio in Lumbar Paraspinal Muscle of Patient with Herniated Intervertebral Lumbar Disc (요추간판 수핵 탈출증 환자의 요부 척추 주위근 내 지방침윤 비율에 관한 연구)

  • Kong, Bong-Jun;Lee, Jung-Ho;Yong, Min-Sik;Kim, Jin-Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5254-5260
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    • 2012
  • The purpose of this study is to find the relationship between lumber Herniated Nuclesus Pulposus of specific part and fat infiltration in paraspinal muscle. Also we intended to find the relationship between Body Mass Index(BMI) and fat infiltration ratio in the lumber paraspinal muscle based on the sexes of patients. We conducted this study of patients who visited our hospital from May, 2010 to May, 2012. The subjects are composed of 40 patients(20 females and 20 males), who are 30 to 50 years old suffering from severe lumber herniated nuclesus pulposus, who had or were going to have operation treatment. BMI is measured through anthropometry of each patient and fat infiltration inside the muscle is estimated by measuring the cross section area of lumbar paraspinal muscle from mid-cross section of disc(L2-S1) and fat infiltration ratio. The data of this study are analyzed by independent t-test to figure out the difference of fat infiltration between male and female, and by paired sample T-test after getting mean and standard deviation to find the changes of fat infiltration of lumbar on each level. Also correlation analysis is done by setting age as a control variable to find the correlation between BMI and fat infiltration of the whole lumbar. As a result, we could get only the meaningful difference between the sexes on upper lumber part(L2-L3) while we couldn't find any significant difference in the rest of lumbar(L3-S1). Besides, the changes of fat infiltration ratio on each lumbar level increased rapidly from lumbar 3,4 to lumbar 4,5. We also found that there is no correlation between fat infiltration ratio of lumbar paraspinal muscle(L2-S1) and BMI.

Validation of Load Calculation Method for Greenhouse Heating Design and Analysis of the Influence of Infiltration Loss and Ground Heat Exchange (온실 난방부하 산정방법의 검증 및 틈새환기와 지중전열의 영향 분석)

  • Shin, Hyun-Ho;Nam, Sang-Woon
    • Horticultural Science & Technology
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    • v.33 no.5
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    • pp.647-657
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    • 2015
  • To investigate a method for calculation of the heating load for environmental designs of horticultural facilities, measurements of total heating load, infiltration rate, and floor heat flux in a large-scale plastic greenhouse were analyzed comparatively with the calculation results. Effects of ground heat exchange and infiltration loss on the greenhouse heating load were examined. The ranges of the indoor and outdoor temperatures were $13.3{\pm}1.2^{\circ}C$ and $-9.4{\sim}+7.2^{\circ}C$ respectively during the experimental period. It was confirmed that the outdoor temperatures were valid in the range of the design temperatures for the greenhouse heating design in Korea. Average infiltration rate of the experimental greenhouse measured by a gas tracer method was $0.245h^{-1}$. Applying a constant ventilation heat transfer coefficient to the covering area of the greenhouse was found to have a methodological problem in the case of various sizes of greenhouses. Thus, it was considered that the method of using the volume and the infiltration rate of greenhouses was reasonable for the infiltration loss. Floor heat flux measured in the center of the greenhouse tended to increase toward negative slightly according to the differences between indoor and outdoor temperature. By contrast, floor heat flux measured at the side of the greenhouse tended to increase greatly into plus according to the temperature differences. Based on the measured results, a new calculation method for ground heat exchange was developed by adopting the concept of heat loss through the perimeter of greenhouses. The developed method coincided closely with the experimental result. Average transmission heat loss was shown to be directly proportional to the differences between indoor and outdoor temperature, but the average overall heat transfer coefficient tended to decrease. Thus, in calculating the transmission heat loss, the overall heat transfer coefficient must be selected based on design conditions. The overall heat transfer coefficient of the experimental greenhouse averaged $2.73W{\cdot}m^{-2}{\cdot}C^{-1}$, which represents a 60% heat savings rate compared with plastic greenhouses with a single covering. The total heating load included, transmission heat loss of 84.7~95.4%, infiltration loss of 4.4~9.5%, and ground heat exchange of -0.2~+6.3%. The transmission heat loss accounted for larger proportions in groups with low differences between indoor and outdoor temperature, whereas infiltration heat loss played the larger role in groups with high temperature differences. Ground heat exchange could either heighten or lessen the heating load, depending on the difference between indoor and outdoor temperature. Therefore, the selection of a reference temperature difference is important. Since infiltration loss takes on greater importance than ground heat exchange, measures for lessening the infiltration loss are required to conserve energy.

Analysis of Effectiveness for Water Cycle and Cost-Benefit according to LID Application Method in Environmentally-Friendly Village (친환경시범마을의 LID 적용에 따른 물순환 효과 및 비용편익 분석)

  • Baek, Jongseok;Lee, Sangjin;Shin, Hyunsuk;Kim, Hyungsan
    • Journal of Korean Society on Water Environment
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    • v.34 no.1
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    • pp.57-66
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    • 2018
  • Water disasters such as flash floods and inundation caused by localized heavy rainfall in urban areas have a large impact on climate change but are also closely related to the increase in impervious areas as pointed out in domestic and international studies. It is difficult to secure natural green areas in urban areas that have already been developed. So, urban regeneration can be expected using water management optimized with technologies to secure infiltration and storage capacity such as Low-Impact Development technology. In this study, the water cycle improvement ability was confirmed by applying the LID technology within the district unit plan of the environmentally friendly village, and the economic feasibility of LID application was analyzed by estimating the costs and benefits of installing the facilities. The site was planned to conserve sufficient green and plans for securing the watershed infiltration and storage capacity were formulated with the application of additional LID technology, such as infiltration trenches, rain barrels and permeable pavements. The LID design method applicable to the site was established, and the water balance of the watershed was analyzed through simulations of the SWMM model. The water circulation improvement effect was confirmed through the water balance analysis, and the cost-benefits were determined according to the estimation method, and the economic analysis was conducted. This study confirms that the investment of LID technology is economically feasible for the hydrological improvement effect of the housing complex.

Analysis of an Actual Slope Failure in the Residual Soil by Suction Stress Based Effective Stress (흡수응력에 기반한 유효응력에 의한 실제 잔류토 사면 붕괴의 해석)

  • Oh, Seboong;Lu, Ning;Park, Young Mog;Lee, Junsuk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.3C
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    • pp.113-120
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    • 2012
  • An actual slope failure was analyzed in residual soils at Jinju. Due to rainfall infiltration, the safety factor decreases in the unsaturated layers, since the effective stress and shear strength decrease. In this study, the effective stress is based on suction stress using soil water retention curve. Unsaturated properties were evaluated on soil water retention curve, hydraulic conductivity and shear strength with samples from the site. After infiltration analysis of unsaturated flow under the actual rainfall, the distribution of pore water pressure could be calculated in the slope layers. In the stress field of finite elements, an elastic analysis calculated total stress distribution in the layers and also shear stresses on the slip surface using elastic model. On the slip surface, suction stress and effective stress evaluated the shear strength. As a result, the factor of safety was calculated due to rainfall, which could simulate the actual slope failure. In particular, it was found that the suction stress increases and both the effective stress and the shear strength decrease simultaneously on the slip surface.